Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gastric juice from 15 normals, 20 patients with gastric ulcer and 14 patients with erosive haemorrhagic gastroduodenitis was investigated in respect of its activity on unheated and heated fibrin plates and its content of FDP and plasminogen or plasmin with immunochemical methods. Gastric juice from normals showed no activity on unheated and heated fibrin plates, and no FDP or plasminogen could be demonstrated. In the patients with gastric ulcer the gastric juice showed little or no fibrinolytic activity on fibrin plates except in 2, who had regurgitation of duodenal juice and neutral pH of the juice. These patients had equally high activity on heated as on unheated plates and no plasmin could be demonstrated. It was shown that this activity was not due to fibrinolysis, but to non-specific proteolytic activity (probably trypsin). The patients with erosive haemorrhage gastroduodenitis exhibited quite a different picture. The gastric juice from these patients showed extremely high activity on fibrin plates, the activity was higher on unheated than on heated plates. The activity was inhibited in vitro by addition of EACA and in vivo after administration of AMCA. The occurence of plasmic could be demonstrated directly immunologically in the gastric juice. By comparsion of plasmin and trypsin in various assays it could further be improved that the gastric juice in these cases contained plasminogen activator and plasmin. The patients with erosive haemorrhagic gastroduodenitis showed no increase in fibrinolysis in the blood, but low values for plasminogen and alpha2-M, and the serum contained FDP. These findings in the blood and gastric juice were interpreted as signs of local fibrinolysis in the stomach and duodenum. There is reason to assume that this gastric fibrinolysis contributes substantially to the bleeding tendency. The effect of administration of AMCA on fibrinolytic activity and the haemorrhage lends support to the assumption of such a mechanism.
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PMID:Gastric fibrinolysis. 0 Aug 7

A modification of the fibrin plate method is presented. Plasminogen-free human fibrinogen and plasminogen purified by affinity chromatography have been used. Fibrin plates without and with a constant amount of plasminogen and with agarose as stabilizing medium were used for the estimation of plasmin and plasminogen activator activity. Activator activity could be demonstrated in sterile bile and saliva. When plasmin activity was present, estimations of plasminogen activator were approximate. The method is sensitive, small volumes of reagents and samples are needed. The error of the method is comparatively low and the reproducibility is good.
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PMID:Fibrin plate method with reagents purified by affinity chromatography and its use for determination of fibrinolytic and other proteolytic activity in saliva, bile and plasma. 0 32

Psoriatic scale proteases were found to be extracted effectively in salt solution (1 mol/l) containing Triton X-100 (5 g/l). The extraction in dilute buffer or sucrose yielded low activities. The acid (0.25 N H2SO4) and KSCN (2 mol/l) solutions effectively extracted plasminogen activator. Fibrinolysin was most active in salt (1 mol/l KCl) and in KSCN (2 mol/l) extracts. Psoriatic scale proteases were fractionated by Sephadex G-100 gel filtration and further by DEAE cellulose chromatography. Five different enzyme preparations were obtained. The first preparation, resembling cathepsin D, effectively hydrolysed hemoglobin at pH 3.5 and casein at pH 5.8 and was insensitive to protease modifiers. The second preparation effectively hydrolysed trypsin substrates (AGLME, TAME, BAEE and BANA) and also histone and casein at pH 7.2 and was inhibited by protease inhibitors, TLCK and E-600. The third preparation hydrolysed histone and casein at pH 10.2 and was effectively inhibited by E-600 and partially by protease inhibitors and TPCK. The fourth preparation, resembling cathepsin B1, hydrolysed BANA and BAEE at pH 5.8 and was activated by SH-reagents and EDTA. The fifth enzyme preparation hydrolysed ATEE and was inhibited by E-600 and TPCK. Plasminogen activator was found mainly in the second enzyme preparation and fibrinolysin activity in the third and fifth enzyme preparations. The second, third and fifth enzyme preparations were different from the enzymes found in healthy human skin. The proteases of psoriatic scale resemble those of tissue and cell cultures undergoing rapid cell division. The possible role of proteases in the increased cell division in psoriasis plaque is discussed.
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PMID:Human skin proteases. Fractionation of psoriasis scale proteases and separation of a plasminogen activator and a histone hydrolysing protease. 0 31

This recent study describes the growth characteristics of ACR skin fibroblasts in culture and their differential susceptibility to transformation by Kirsten murine sarcoma virus (Ki-MSV). The SF were derived from normal appearing subepidermoid biopsies of ACR individuals, their progeny and ocntrols. Normal SF were contact-inhibited and grew only in 15% FCS. SF of ACR subjects, and some asymptomatic ACR progeny were not contact inhibited, grew in both 1% and 15% FCS and were considerably more susceptible to transformation by Ki-MSV than were control SF. The virally transformed SF showed a loss of anchorage dependency in methylcellulose and formed tumors in athymic mice. The results suggest the presence of early and previously undetected metabolic lesions in SF from clinically asymptomatic subjects. These phenotype markers are currently evaluated for their utility in the clinical diagnosis of individuals with latent ACR and those at increased risk for colon cancer. SF from ACR individuals have been recently shown to contain significant alterations in the intracellular distribution of actin (R. Pollack and L. Kopelovich, in preparation), and elevated levels of plasminogen activator (L. Kopelovich).
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PMID:Recent studies on the identification of proliferative abnormalities and of oncogenic potential of cutaneous cells in individuals at increased risk of colon cancer. 1 61

It has previously been shown, that large differences exist between the effects of 6-aminohexanoic acid or alpha1-antitrypsin on fibrinolysis caused by a porcine tissue plasminogen activator or by human urokinase, while insignificant differences exist between the effects of a number of natural protease inhibitors on fibrinolysis caused by the two types of plasminogen activator. The present study shows that changes in substrate composition (pH, ionic strength fibrinogen concentration, plasminogen concentration) may influence to different degrees the fibrinolytic activities of human urokinase and the porcine tissue plasminogen activator. It is suggested, that this finding is partly related to marked differences in affinity for fibrin of the two activators.
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PMID:Differences in the reactivities of human urokinase and the porcine tissue plasminogen activator. 1 58

A plasminogen activator secreted by cultured human pancreatic carcinoma (Mia PaCa-2) cells has been purified to apparent homogeneity by procedures including Sepharose-L-arginine methyl ester affinity chromatography, Sephadex G-200 gel filtration, isoelectric focusing, and sodium dodecyl sulfate gel electrophoresis. The plasminogen activator shares many properties with urokinase including: molecular weight (55 000), isoelectric point (8.7), heat stability (60 degrees C, 30 min), PH stability (1.5-10), and its mode of activation of plasminogen. The intracellular enzyme is membrane bound and can be solubilized by detergent. Solubilized activator has a molecular weight similar to that of the secreted enzyme as determined by sodium dodecyl sulfate gel electrophoresis. The production of plasminogen activator by Mia PaCa-2 cells is totally inhibited by actinomycin D and cycloheximide.
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PMID:Purification and characterization of a plasminogen activator secreted by cultured human pancreatic carcinoma cells. 1 90

Cultured normal low-passage embryo fibroblasts, from a number of species, and two untransformed clones of a Balb/3T3 line elaborate increasing amounts of plasminogen activator (PA) as they approach confluence; the low-passage cells then lose this PA activity after reaching confluence, while the 3T3 cells retain it indefinitely. Even at their peaks, however, the PA activities of the low-passage cells remain well below those of the corresponding virally or spontaneously transformed cells. The PA increases in normal cells are probably a result of PA production rather than of adsorption of secreted PA to the cell surface, or of changes in cell-associated protease inhibitors. The elaboration of PA by normal cells is dependent upon their metabolic activity, such that the level of serum supplementation and the growth phase of the culture directly influence the level of cell-associated PA observed. In addition, there may be a component of serum which exerts a negative control on PA production and which is not an acid-labile protease inhibitor.
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PMID:Patterns of plasminogen activator production in cultured normal embryonic cells. 2 Nov 93

From the supernatant of B. melaninogenicus ss. asaccharolyticus culture, a protein fraction was isolated by ethanol precipitation. The fraction was tested for the presence of clotting and fibrinolytic activities by application of quantitative techniques and specific substrates for measurement of prothrombin and plasminogen activation, and collagenase and elastase activity. It is postulated that ability of Bacteroides melaninogenicus ss. asaccharolyticus extracellular factors to clot fibrinogen and activate plasminogen, are due to a limited proteolysis by the proteolytic enzymes produced by this microorganism and not to the existence of specific B. melaninogenicus coagulase of plasminogen activator.
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PMID:The nature of clotting and fibrinolytic activities of Bacteroids melaninogenicus. 2 65

Peritoneal macrophages were obtained from untreated mice and from mice treated with thioglycollate medium (TA), proteose peptone medium (PP), or a suspension of streptococcus A cell wall material (SA). The biochemical and secretory properties of these cells in long term cultures (up to 2 wk) were compared. TA-elicited macrophages contained more protein, lactate dehydrogenase, lysosomal hydrolases, and in particular, more plasminogen activator than the other cells studied. All types of macrophages studied were found to release considerable amounts of lysosomal hydrolases (beta-glucuronidase, N-acetyl-beta-glucosaminidase, alpha-mannosidase, and acid phosphatase) into the medium. Release was independent of phagocytosis and must, therefore, be regarded as true secretion. In both elicited and nonelicited macrophages, the rates of lysosomal enzyme secretion were virtually identical in the presence and in the absence of serum, and they were not enhanced by increasing serum concentrations. Lysosomal enzyme secretion in macrophages appears to depend on protein synthesis, since it was blocked by low concentrations of cycloheximide which neither affected cell viability nor lowered the intracellular enzyme levels. The amounts of lysosomal hydrolases secreted were highest in TA-elicited macrophages. The rates of secretion of PP- or SA-elicited and of nonelicited macrophages were about one-fourth of that of the TA-elicited cells. This difference, although significant, is much smaller than that observed for the secretion of plasminogen activator which was 20-50 times higher in TA-elicited cells. Acid glycosidases were also found in the peritoneal lavage media used for cell harvesting from both treated and nontreated mice. This indicates that active secretion of lysosomal hydrolases may be an in vivo property of the macrophage.
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PMID:Secretion of lysosomal hydrolases by stimulated and nonstimulated macrophages. 2 35

Non-enzyme fibrinolytic agents include pharmacological agents which are active in vivo but inactive in vitro and synthetic chemical compounds which when added to blood or plasma in vitro directly induce fibrinolysis. There are a number of drugs with a short duration of action such as adrenalin, nicotinic acid, vasopressin and histamine. Vasoactive drugs probably act by stimulating the liberation of vascular activator. The effect of nicotinic acid is rapidly exhausted when injections are repeated. By contrast, the biguanides and certain anabolic steroids are capable of exerting a long term stimulation of endogenous fibrinolysis. Amongst these substances, phenformin, metformin, ethyloestrenol, stanozolol and a new substance, moroxydine chloride, have been studied. The biguanides appear to be capable of exerting an effect upon the synthesis and liberation of plasminogen vascular activator. The combination of an anabolic steroid and a biguanide would appear to be the most powerful. These various drugs have been used with success in cases of recurrent venous thrombosis in patients with an abnormally low level of plasminogen activator in the venous walls and/or low fibrinolytic activity after venous stasis. Chemical fibrinolytic agents were studied only in vitro, since the use of these substances in human therapeutics would seem to be still difficult in view of the fact that they are active only in a narrow range of concentrations.
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PMID:[Non-enzymatic fibrinolytic agents]. 3 Nov 13


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